Results 81 to 90 of about 460,881 (203)
Advanced Powder MaterialsAchieving optimal mechanical properties, including hardness and fracture toughness, by controlling grain size is a fundamental and long-standing objective in the development of hard and superhard transition metal borides (TMBs) ceramics.
Shuailing Ma +12 more
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NP-hardness and inapproximability of sparse PCA [PDF]
Information Processing Letters, 2017 We give a reduction from {\sc clique} to establish that sparse PCA is NP-hard. The reduction has a gap which we use to exclude an FPTAS for sparse PCA (unless P=NP). Under weaker complexity assumptions, we also exclude polynomial constant-factor approximation algorithms.
openaire +3 more sources
Computational Aspects of Lucidity-Driven Graph Clustering
Journal of Graph Algorithms and Applications, 2010 We formally state and investigate the lucidity paradigm for graph clusterings. The rationale that substantiates this concept is the trade-off between the achieved quality and the expected quality of a graph clustering.
Robert Görke +3 more
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A new method for hardness determination from depth sensing indentation tests [PDF]
, 1996 A new semiempirical formula is developed for the hardness determination of the materials from depth sensing indentation tests. The indentation works measured both during loading and unloading periods are used in the evaluation.
Juhász, A. +2 more
core +1 more source
Communication Complexity is NP-hard
CoRRIn the paper where he first defined Communication Complexity, Yao asks: \emph{Is computing $CC(f)$ (the 2-way communication complexity of a given function $f$) NP-complete?} The problem of deciding whether $CC(f) \le k$, when given the communication matrix for $f$ and a number $k$, is easily seen to be in NP.
Shuichi Hirahara +2 more
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Hardness of approximation for orthogonal rectangle packing and covering problems [PDF]
, 2009 Bansal and Sviridenko [N. Bansal, M. Sviridenko, New approximability and inapproximability results for 2-dimensional bin packing, in: Proceedings of the 15th Annual ACM–SIAM Symposium on Discrete Algorithms, SODA, 2004, pp.
Chlebikova, Janka +4 more
core +1 more source
On Basing Search SIVP on NP-Hardness [PDF]
, 2018 The possibility of basing cryptography on the minimal assumption NP$\nsubseteq$BPP is at the very heart of complexity-theoretic cryptography. The closest we have gotten so far is lattice-based cryptography whose average-case security is based on the ...
Tianren Liu
core +2 more sources
Alexandria Engineering Journal, 2018 The influences of Nano particles incorporation, fiber type and matrix types on the mechanical properties of fiber-reinforced composites have been widely investigated by researchers.
Yasser S. Mohamed +2 more
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Hardness Evaluation of Porous Hydroxyapatite Coating [PDF]
, 2007 The extensive use of appropriate coatings to improve wear resistance, friction coefficient, electrical properties, corrosion resistance and biomedical application has stimulated a growing interest in their mechanical properties and especially hardness ...
A. Iost +7 more
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Co-Clustering under the Maximum Norm
Algorithms, 2016 Co-clustering, that is partitioning a numerical matrix into “homogeneous” submatrices, has many applications ranging from bioinformatics to election analysis. Many interesting variants of co-clustering are NP-hard.
Laurent Bulteau +3 more
doaj +1 more source